What word names the 250th anniversary celebrated by America250?

The word “semiquincentennial” names the 250th anniversary celebrated by America250.

The term combines “semi,” meaning half, with “quincentennial,” relating to 500 years. A 250th anniversary is therefore half of a 500-year milestone. The United States Semiquincentennial marks 250 years since the Declaration of Independence was adopted in 1776.

Several alternative names appear in historical and media discussions, including “bisesquicentennial,” “sestercentennial,” and “quarter millennium.” Semiquincentennial is the formal name used by the congressional United States Semiquincentennial Commission and the America250 initiative.

The term is easy to confuse with “sesquicentennial,” which means a 150th anniversary, and “bicentennial,” which means a 200th anniversary. “Tricentennial” means 300 years, so it describes a later milestone rather than the 2026 commemoration.